1. Field of Invention
The present invention relates to an electrooptic device and an electronic device in which a peripheral circuit is formed on a substrate. More particularly, the present invention relates to a technique of laying out the peripheral circuit on the substrate.
2. Description of Related Art
In recent years, electrooptic devices represented by liquid crystal devices and EL (electroluminescence) display panels have attracted attention as display sections in electronic devices, such as portable telephones, portable computers, and video cameras. For example, as shown in FIG. 18, in an active matrix liquid crystal device using a thin-film transistor as a pixel switching element, of such electrooptic devices, a TFT array substrate 10 having pixel electrodes and pixel-switching TFTs (both not shown) formed on a transparent substrate, and a counter substrate 20 having counter electrodes (not shown) formed on a transparent substrate are bonded with a sealing material 107 with a predetermined space therebetween, and liquid crystal serving as an electrooptic substance is held between the substrates.
As shown in FIG. 19, when the orthogonal directions are designated X- and Y-directions, a plurality of pixels 100a are formed at a predetermined pitch and in a matrix on the TFT array substrate 10 corresponding to the intersections of a plurality of data lines 6a extending in the Y-direction and a plurality of scanning lines 3a extending in the X-direction, and a region in which these pixels 100a are arranged in a matrix forms an image display region 10a in which actual display is produced.
In a portion adjoining the image display region 10a in the Y-direction, of a region around the image display region 10a, a data-line driving circuit 101 is formed which includes shift register circuits 101b, sample hold circuits 101c having analog switches to be operated in response to signals output from the shift register circuits 101b, six image signal lines 110d corresponding to six-phase image signals, and the like. In the data-line driving circuit 101, the shift register circuits 101b, the sample hold circuits 101c, and the like are formed in the regions extending in the Y-direction from the forming regions of the data lines 6a and the pixel rows connected thereto in a one-to-one correspondence with the data lines 6a and pixel rows connected thereto. Consequently, the X-direction pitch of the shift register circuits 101b and the like is equal to the X-direction pitch of the pixel rows.
As shown in FIGS. 18 and 19, scanning-line driving circuits 104 are formed on the periphery of the image display region 10a so that they are connected to the scanning lines 3a, and a plurality of lines 109 are routed from terminals 102 so as to supply signals to the scanning-line driving circuits 104 and the data-line driving circuit 101.
Conductive electrodes 9g are formed in the regions on the periphery of the image display region 10a that overlap with the counter substrate 20, and are electrically connected to the counter electrodes of the counter substrate 20 through conductive materials 106 held between the substrates. Therefore, a constant voltage (DCCOM) supplied to the terminals 102 of the TFT array substrate 10 can be supplied to the counter electrodes of the counter substrate 20.
In the liquid crystal device 100 having such a configuration, when trouble occurs during the production process of the TFT array substrate 10, and the TFT malfunctions, a display defect, such as a point defect and a line defect, is caused, and therefore, it is necessary to follow the production history. For this reason, in the liquid crystal device 100, identification marks 40 of, for example, 2 mm 2 mm that indicate the part numbers of the TFT array substrate 10 and the liquid crystal device 100 are put on the TFT array substrate 10. The identification marks 40 are required to be visible or mechanically readable after the TFT array substrate 10 and the counter substrate 20 are bonded together. Therefore, the identification marks 40 are formed in an extended portion 10c of the TFT array substrate 10 that protrudes from the edge of the counter substrate 20 so that the terminals 102 are exposed.